My pool system has an automatic Jandy valve that rotates between enabling the skimmers and enabling the pool vacuum port. Years ago, I "tuned" its stop point so that the vacuum port got only enough flow to run the vacuum properly (too much and you overpower the vacuum and it stops running). The portion of the flow that doesn't go to the vacuum goes to the skimmers, which is an efficient use of the pump power.
Recently my pump died and I replaced it with one of the multi-speed pumps that the local utility is promoting to save energy. Since the pump runs at several speeds at different times of day, it's now impossible to use just the Jandy turn-limit switch to tune the "correct" flow range for the vacuum.
The rigorous way to do this would be to install a flow sensor in the pipe running to the vacuum, and gen up a little control box that rotates the Jandy valve in the proper direction until the sensor says the vacuum flow is within spec. Either that, or find an automatic valve with a flow-rate feature built in, which would be stupendous.
But I haven't been able to find anything that fits the bill. There are cheap flow sensors, but either they just read "flowing/not flowing" or don't play well in the typical chlorine level of a pool. There are flow sensors that do what I want, but they are scientific-grade construction and start at four figures.
Is there an available pool-quality dingus that will do what I need?
